JP2016045268A - Developing device and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device 9 arranging a development blade lower seal member 36 and development end part seal members 34L and 34R on the rear surface of a development blade 31, capable of suppressing repulsive force of the development blade lower seal member 36 and the development end part seal members 34L and 34R to the development blade 31 to prevent the end parts of the development blade 31 from being increased in pressure and equalize the contact pressure of the development blade 31 in a longitudinal direction and less in variation of image density in the longitudinal direction.SOLUTION: In a position including coupling parts 80L and 80R in which the development blade lower seal member 36 is overlapped with the development end part seal members 34L and 34R in the longitudinal direction of the development blade 31, a support metal plate 32 forms projection parts 71L and 71R and suppresses the coupling parts 80L and 80R or the development blade lower seal member 36.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a developing device used in an electrophotographic image forming apparatus such as a copying machine or a printer that employs an electrophotographic system.

  Here, the electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic system. Examples of the electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer, etc.), a facsimile machine, a word processor, and the like.

  The developing device is a device in which developing means used for developing the electrostatic latent image on the electrophotographic photosensitive member is integrated. Alternatively, the developing device alone is detachably mounted on the electrophotographic image forming apparatus.

  The developing device is a device in which developing means used for developing the electrostatic latent image on the electrophotographic photosensitive member is integrated, and forms a part of the process cartridge, or the developing device alone is an electrophotographic image. It is detachably mounted on the forming apparatus.

  Further, the process cartridge is a cartridge in which at least one of charging means, developing means, and cleaning means as process means and an electrophotographic photosensitive member as an image carrier are integrally formed, and this cartridge is used for the electrophotographic image forming apparatus. It is intended to be detachable.

  An electrophotographic image forming apparatus such as a printer using an electrophotographic process uniformly charges an electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum) which is an image carrier, and selectively selects the electrophotographic photosensitive member. A latent image is formed by simple exposure. The latent image is developed with a developer (hereinafter referred to as toner), and becomes a developer image. Then, the developer image is transferred to a recording medium. By applying heat or pressure to the transferred developer image, the developer image is fixed on a recording medium to record an image.

  Conventionally, such an electrophotographic image forming apparatus involves toner replenishment and maintenance of various process means. As a means for facilitating the toner replenishment work and maintenance, all or a part of the photosensitive drum, charging means, developing means, cleaning means, etc. can be combined into a cartridge to be detachable from the image forming apparatus. The process cartridge method is adopted.

  According to this process cartridge system, the user can perform maintenance of the apparatus in the form of replacement of the process cartridge, the developing device, and the cleaning device, so that the operability can be remarkably improved. Therefore, this process cartridge system is widely used in image forming apparatuses.

  The developing device includes a developing frame that contains a developer, and a developer carrier (hereinafter referred to as a developing roller) is rotatably installed in an opening of the container facing the photosensitive drum. A developing blade, which is a developer regulating member, is disposed above the developing roller and is in contact with the developing roller with a predetermined pressure. This developing blade regulates the layer thickness of the developer carried on the developing roller, and applies and forms the developer layer. The developing blade is formed of, for example, a stainless steel thin plate having a thickness of 100 μm, and a short portion of the developing blade is formed on a supporting sheet metal formed of, for example, a steel plate having a thickness of 1 mm in the entire axial direction of the developing roller (hereinafter referred to as a longitudinal direction). (The developing blade unit is referred to as the one integrated with the supporting sheet metal).

  The contact pressure of the developing blade to the developing roller can be controlled by changing the distance from the support metal plate to the tip of the developing blade. Details will be described later.

  The developing device includes a developing blade lower seal member and a developing end seal as a developer leakage preventing member for preventing toner leakage between the developing roller and the developing frame and between the developing blade unit and the developing frame. It has a member.

  The developing blade lower seal member, which is the first developer leakage preventing member, is a cushion layer made of an elastic polyurethane foam or the like, and is in close contact between the developing frame and the developing blade unit on the back side of the developing blade unit. This prevents the toner from leaking outside.

  The developing end seal member, which is the second developer leakage prevention member, is composed of a surface layer and an intermediate layer. For example, a nonwoven fabric is used for the surface layer, and a cushion layer such as foamed polyurethane is used for the intermediate layer. The developing end seal member is disposed near one end in the longitudinal direction of the developing roller and between the developing roller and the developing frame near the other end to prevent the toner from leaking out from the developing roller end. Yes.

  Further, the development blade unit is supported on the development frame body by screws or the like on support seat surfaces formed at both ends in the longitudinal direction with respect to the development frame body. Therefore, when the developing roller is brought into contact with the developing blade, the center in the longitudinal direction of the developing blade is deformed by the contact repulsive force with the developing roller and is displaced in a direction away from the developing roller. As a result, the end pressure is higher than the central pressure.

  When the contact pressure in the longitudinal direction is different, the charge imparting ability varies depending on the position in the longitudinal direction. For this reason, the density of the image density is likely to appear depending on each position in the longitudinal direction.

  As an example of the prior art, at both ends in the longitudinal direction, the support sheet metal is partially cut away in a direction perpendicular to the longitudinal direction, and the free length of the developing blade (the distance from the tip of the developing blade to the point supported by the supporting sheet metal) Has been proposed in which both ends are longer than the center (Patent Document 1). As a result, the contact pressure of the developing blade to the developing roller at both ends can be set lower than the center, and the contact pressure in the longitudinal direction can be made uniform.

JP-A-7-160116

  An object of the present invention is to further improve the above-described technique, and to provide a developing device with less image density in the longitudinal direction by making the contact pressure in the longitudinal direction of the developing blade uniform. is there.

  In order to achieve the above-mentioned object, an invention relating to the present application includes a developing frame housing a developer, a developer carrying body carrying the developer, and one end portion in a direction perpendicular to the axis of the developer carrying body, In the developing device having a developer regulating member that regulates the developer on the developer carrying body by being brought into contact with the developer carrying body, the development regulating member includes a developing blade that is in contact with the developer carrying body, and development A support sheet metal that supports the blade, the support sheet metal has a contact area that contacts the developing blade, the development blade is coupled to the support sheet metal in the contact area, the support sheet metal is attached to the development frame body, and the developer carrying body A first developer leakage preventing member which is fixed at both ends in the axial direction and seals between the development regulating member and the developing device frame in the axial direction of the developer bearing member; and both ends in the axial direction of the developer bearing member In the developer carrier A second developer leakage preventing member that seals between the developing frame members and between the development regulating member and the developing frame member, and the axial direction of the developer carrying member of the first developer leakage preventing member Development restricting member in a direction orthogonal to the axis of the developer carrying member in the end region in the axial direction of the developer carrying member. The distance between the one end of the developing member and the contact area is a first distance, and the inner side of the protruding portion has one end of the development regulating member in the direction perpendicular to the axis of the developer carrier. The distance to the contact area has a second area that is a second distance, and on the inner side in the longitudinal direction of the second area, one end of the image regulating member in a direction orthogonal to the axis of the developer carrier The distance to the contact area has a third area that is the third distance, and the first distance and the second distance. The relationship between the third distance is the second distance> the first distance ≧ the third distance, and the protruding portion suppresses at least a part of the first developer leakage preventing member. .

  According to the present invention, the repulsive force received from the first developer leakage preventing member or the second developer leakage preventing member disposed at both ends in the longitudinal direction is received by the thin developing blade, and the developing blade is on the developing roller side. It is possible to prevent an increase in the contact pressure of the developing blade against the developing roller, which occurs due to the deformation.

  That is, the first developer leakage prevention member or the second developer leakage prevention is obtained by receiving the repulsive force of the first developer leakage prevention member or the second developer leakage prevention member with a rigid support metal plate. The repulsive force of the member can be prevented from exerting on the contact pressure of the developing blade to the developing roller.

  As a result, it is possible to provide a developing device in which the contact pressure to the developing roller is made uniform in the longitudinal direction of the developing blade and the image density in the longitudinal direction is low.

FIG. 2 is an exploded perspective view and a completed perspective view illustrating an example of a configuration of a developing blade unit according to the present invention. 1 is a schematic cross-sectional view showing an example of an electrophotographic image forming apparatus according to the present invention. The perspective view and sectional view showing an example of the process cartridge concerning the present invention 1 is a schematic cross-sectional view showing an example of mounting a process cartridge to an electrophotographic image forming apparatus according to the present invention. Schematic cross-sectional view showing an example of removal of a process cartridge from an electrophotographic image forming apparatus according to the present invention 1 is an exploded perspective view showing an example of a developing device according to the present invention. Sectional drawing which shows an example of the image development apparatus concerning this invention Detailed configuration diagram showing an example of a first developer leakage preventing member according to the present invention Detailed configuration diagram showing an example of a second developer leakage preventing member according to the present invention The perspective view and partial enlarged view which show an example of the affixing process of the 1st developer leak prevention member and the 2nd developer leak prevention member to the image development frame concerning this invention FIG. 3 is an exploded front view showing an example of a process of attaching the developing blade unit to the developing device frame according to the present invention. The partial perspective view which shows an example of the assembly | attachment process of the image development blade unit to the image development frame concerning this invention, a partial front view, and a fragmentary sectional view The partial perspective view which shows an example of the assembly | attachment process of the image development blade unit to the image development frame concerning this invention, a partial front view, and a fragmentary sectional view The partial perspective view which shows an example of the assembly | attachment process of the developing blade unit to the developing device frame concerning this invention, and a partial front view The partial perspective view which shows an example of the assembly | attachment process of the developing blade unit to the developing device frame concerning this invention, and a partial front view

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  Hereinafter, the present embodiment will be described with reference to FIGS. In the following embodiments, as the electrophotographic image forming apparatus, a full-color electrophotographic image forming apparatus in which four process cartridges including a developing device are detachable is illustrated. However, the number of process cartridges attached to the electrophotographic image forming apparatus (hereinafter referred to as image forming apparatus) is not limited to this. It is appropriately set as necessary.

  For example, in the case of an image forming apparatus that forms a monochrome image, the number of process cartridges attached to the image forming apparatus is one. Further, according to the embodiment described below, a printer is exemplified as one aspect of the image forming apparatus. However, the present invention is not limited to this. For example, the present invention can also be applied to other image forming apparatuses such as a copying machine and a facsimile machine, or other image forming apparatuses such as a multi-function machine combining these functions.

  In this embodiment, a process cartridge including a developing device will be described. However, other configurations may be used in carrying out the present invention. For example, the developing device may be detachable from the image forming apparatus, or may be configured such that the developing device is incorporated in the image forming apparatus and cannot be detached.

<< Schematic Configuration of Image Forming Apparatus >>
First, a schematic cross-sectional view of the image forming apparatus of this embodiment is shown in FIG. The image forming apparatus 1 is a four-color full-color laser printer using an electrophotographic process, and forms a color image on a recording medium S. The image forming apparatus 1 is a process cartridge type, and a process cartridge (hereinafter referred to as a cartridge) is detachably attached to the apparatus main body 2 to form a color image on the recording medium S.

  Here, regarding the image forming apparatus 1, the side on which the apparatus opening / closing door 3 is provided is defined as a front surface (front surface), and the surface opposite to the front surface is defined as a back surface (rear surface). Further, when the image forming apparatus 1 is viewed from the front, the right side is referred to as a driving side, and the left side is referred to as a non-driving side.

  In the apparatus main body 2, four cartridges P (PY, PM, PC, PK) of the first cartridge PY, the second cartridge PM, the third cartridge PC, and the fourth cartridge PK are arranged in the horizontal direction. .

  Each of the first to fourth cartridges P (PY, PM, PC, PK) has the same electrophotographic process mechanism, and the developer colors are different from each other. A rotational driving force is transmitted to the first to fourth cartridges P (PY, PM, PC, PK) from a drive output unit (not shown) of the apparatus main body 2. A bias voltage (charging bias, developing bias, etc.) is supplied from the apparatus main body 2 to each of the first to fourth cartridges P (PY, PM, PC, PK) (not shown).

  As shown in FIG. 3, each of the first to fourth cartridges P (PY, PM, PC, and PK) of this embodiment is an electrophotographic photosensitive member 4 and a process unit that acts on the photosensitive drum 4. The cleaning unit 8 includes a charging unit and a cleaning unit. Each of the first to fourth cartridges P (PY, PM, PC, PK) includes a developing device 9 including a developing unit that develops the electrostatic latent image on the photosensitive drum 4.

  The cleaning unit 8 and the developing device 9 are coupled to each other. Further, a charging roller 5 is used as a charging unit, a cleaning blade 7 is used as a cleaning unit, and a developing roller 6 is used as a developing unit. A more specific configuration of the cartridge will be described later.

  As shown in FIG. 2, the first cartridge PY contains yellow (Y) toner in the developing frame 29 and forms a yellow toner image on the surface of the photosensitive drum 4. The second cartridge PM contains magenta (M) toner in the developing frame 29 and forms a magenta toner image on the surface of the photosensitive drum 4.

  The third cartridge PC contains cyan (C) toner in the developing frame 29 and forms a cyan toner image on the surface of the photosensitive drum 4. The fourth cartridge PK contains black (K) toner in the developing frame 29 and forms a black toner image on the surface of the photosensitive drum 4.

  Above the first to fourth cartridges P (PY, PM, PC, PK), a laser scanner unit LB as an exposure unit is provided. The laser scanner unit LB outputs a laser beam Z corresponding to the image information. The laser beam Z passes through the exposure window 10 of the cartridge P and scans and exposes the surface of the photosensitive drum 4.

  Below the first to fourth cartridges P (PY, PM, PC, PK), an intermediate transfer belt unit 11 as a transfer member is provided. The intermediate transfer belt unit 11 includes a driving roller 13, a turn roller 14, and a tension roller 15, and a flexible transfer belt 12 is stretched over the intermediate transfer belt unit 11.

  The lower surface of the photosensitive drum 4 of each of the first to fourth cartridges P (PY, PM, PC, PK) is in contact with the upper surface of the transfer belt 12. The contact portion is a primary transfer portion. A primary transfer roller 16 is provided inside the transfer belt 12 so as to face the photosensitive drum 4. A secondary transfer roller 17 is brought into contact with the turn roller 14 via the transfer belt 12. A contact portion between the transfer belt 12 and the secondary transfer roller 17 is a secondary transfer portion.

  A feeding unit 18 is provided below the intermediate transfer belt unit 11. The feeding unit 18 includes a paper feed tray 19 in which recording media S are stacked and accommodated, and a paper feed roller 20.

  A fixing unit 21 and a discharge unit 22 are provided at the upper left in the apparatus main body 2 in FIG. The upper surface of the apparatus body 2 is a discharge tray 23. The recording medium S is fixed with a toner image by fixing means provided in the fixing unit 21 and is discharged to the discharge tray 23.

<Image forming operation>
The operation for forming a full-color image is as follows. The photosensitive drum 4 of each of the first to fourth cartridges P (PY, PM, PC, PK) is rotationally driven at a predetermined speed (counterclockwise in FIG. 2, direction of arrow D in FIG. 3B). As shown in FIG. 2, the transfer belt 12 is also rotationally driven at a speed corresponding to the speed of the photosensitive drum 4 in the forward direction (arrow C direction) with the rotation of the photosensitive drum 4. Then, the laser scanner unit LB is driven.

  In synchronization with the drive of the laser scanner unit LB, the charging roller 5 uniformly charges the surface of the photosensitive drum 4 to a predetermined polarity and potential in each cartridge. The laser scanner unit LB scans and exposes the surface of each photosensitive drum 4 with a laser beam Z according to the image signal of each color. As a result, an electrostatic latent image corresponding to the image signal of the corresponding color is formed on the surface of each photosensitive drum 4. The formed electrostatic latent image is developed by a developing roller 6 that is driven to rotate at a predetermined speed (clockwise in FIG. 2, in the direction of arrow E in FIG. 3B).

  By the electrophotographic image forming process operation as described above, a yellow toner image corresponding to the yellow component of the full color image is formed on the photosensitive drum 4 of the first cartridge PY. Then, the toner image is primarily transferred onto the transfer belt 12. Similarly, a magenta toner image corresponding to the magenta component of the full-color image is formed on the photosensitive drum 4 of the second cartridge PM. The toner image is primary-transferred superimposed on the yellow toner image already transferred onto the transfer belt 12.

  Similarly, a cyan toner image corresponding to the cyan component of the full-color image is formed on the photosensitive drum 4 of the third cartridge PC. Then, the toner image is primary-transferred superimposed on the yellow and magenta toner images already transferred onto the transfer belt 12. Similarly, a black toner image corresponding to the black component of the full color image is formed on the photosensitive drum 4 of the fourth cartridge PK. The toner image is primary-transferred superimposed on the yellow, magenta, and cyan toner images already transferred onto the transfer belt 12.

  In this manner, a full-color unfixed toner image of four colors of yellow, magenta, cyan, and black is formed on the transfer belt 12.

  On the other hand, the recording medium S is separated and fed one by one at a predetermined control timing. The recording medium S is introduced into a secondary transfer portion which is a contact portion between the secondary transfer roller 17 and the transfer belt 12 at a predetermined control timing. As a result, the four color superimposed toner images on the transfer belt 12 are sequentially and collectively transferred onto the surface of the recording medium S while the recording medium S is conveyed to the secondary transfer portion.

<Configuration of cartridge>
FIG. 3A is a perspective view showing an example of a process cartridge according to the present invention, and FIG. 3B is a cross-sectional view showing an example of a process cartridge according to the present invention. As shown in FIG. 3A, the cartridge P (PY / PM / PC / PK) has a horizontally long shape with the direction of the rotation axis a of the photosensitive drum 4 as the longitudinal direction. The apparatus 9 includes a driving side cover member 24 and a non-driving side cover member 25. As shown in FIG. 3B, the cleaning unit 8 includes a photosensitive drum 4, a charging roller 5, and a cleaning container 26 having a cleaning blade 7.

  As shown in FIG. 3A, the photosensitive drum 4 is rotatably supported by a driving-side cover member 24 and a non-driving-side cover member 25. It is driven to rotate by obtaining the driving force (shown) (in the direction of arrow D in FIG. 3B).

  As shown in FIG. 3 (b), the charging roller 5 is rotatably supported at both ends by a charging roller bearing 27 of the cleaning container 26. The charging roller 5 is in contact with the surface of the photosensitive drum 4 and is driven to rotate. The surface of the photosensitive drum 4 is charged by receiving a bias. At this time, both ends of the charging roller 5 are pressed against the surface of the photosensitive drum 4 by the pressure springs 28 in order to uniformly charge the surface.

  The cleaning blade 7 is fixed to the cleaning container 26, and is provided with an elastic rubber portion at the tip thereof in contact with the rotation direction of the photosensitive drum 4 (direction of arrow D in FIG. 3B) in the counter direction. At the time of image formation, the transfer residual toner remaining on the photosensitive drum 4 is scraped to clean the surface of the photosensitive drum 4. At this time, the tip of the cleaning blade 7 is in contact with the surface of the photosensitive drum 4 with a predetermined pressure in order to scrape off the transfer residual toner.

  Further, the transfer residual toner scraped off from the surface of the photosensitive drum 4 by the cleaning blade 7 is stored in the waste toner storage portion 26a of the cleaning container 26 as waste toner. Therefore, a waste toner collection sheet member 44 for preventing leakage of waste toner from the gap between the photosensitive drum 4 and the cleaning blade 7 is fixed to the cleaning container 26 in the longitudinal direction of the photosensitive drum 4. Further, cleaning blade end seal members (not shown) are provided at both longitudinal ends of the cleaning blade 7.

<Cartridge attachment / detachment configuration>
Next, the attaching / detaching operation of the cartridge P (PY / PM / PC / PK) to the apparatus main body 2 will be described. FIG. 4 is a schematic cross-sectional view showing a state in which the cartridge tray 43 is pulled out from the apparatus main body 2 and the cartridge P (PY / PM / PC / PK) is detachable.

  FIG. 5 is a schematic cross-sectional view showing the operation of attaching / detaching the cartridge P (PY / PM / PC / PK) to the cartridge tray 43. A cartridge tray 43 in which a cartridge P (PY / PM / PC / PK) can be mounted is provided in the apparatus main body 2. As shown in FIG. 4, the cartridge tray 43 is configured to be linearly movable (push / pull out) in the G1 and G2 directions which are substantially horizontal with respect to the apparatus main body 2. The cartridge tray 43 can take a mounting position in the apparatus main body 2 and a drawing position pulled out from the mounting position.

  First, the mounting operation of the cartridge P (PY / PM / PC / PK) to the apparatus main body 2 will be described. As shown in FIG. 4, by opening the apparatus opening / closing door 3 and moving the cartridge tray 43 in the direction of the arrow G1, the cartridge tray 43 moves to the drawer position. In this state, as shown in FIG. 5, the cartridge P is mounted and held in the cartridge tray 43 from the direction of the arrow H1. The cartridge tray 43 holding the cartridge P (PY / PM / PC / PK) is moved in the direction of the arrow G2 in FIG. 4, and the cartridge tray 43 is moved to the mounting position in the apparatus main body 2. Then, by closing the device opening / closing door 3, the mounting operation of the cartridge P (PY / PM / PC / PK) to the device main body 2 is completed (FIG. 2).

  On the other hand, the removal of the cartridge P (PY / PM / PC / PK) from the apparatus main body 2 will be described. As shown in FIG. 4, the cartridge tray 43 is moved to the drawer position in the same manner as the mounting operation of the cartridge P to the apparatus main body 2 described above. In this state, the cartridge P is removed in the direction of the arrow H2 in FIG. 5, and the removal operation of the cartridge P from the apparatus main body 2 is completed. With the above operation, the cartridge P can be attached to and detached from the apparatus main body 2.

<Developer configuration>
FIG. 6 is an exploded perspective view showing an example of the developing device according to the present invention. As shown in FIG. 6, the developing device 9 has a horizontally long shape in which the rotation axis direction of the developing roller 6 as the developing means extends in the longitudinal direction. In addition to the developing roller 6, the developing frame 29, the developing blade unit 30, the developer supply roller 33, the developing end seal members 34L and 34R, the flexible sheet member 35, the developing blade lower seal member 36 (not shown), It is constituted by supply roller shaft seals 37L and 37R.

  The developing device frame 29 includes a toner container 29 c for containing toner, and has an opening 29 b for supplying toner from the toner container 29 c to the photosensitive drum 4. The developing roller 6 is disposed so as to include the entire area of the opening 29b in the longitudinal direction in order to carry the toner discharged from the toner storage portion 29c. The developer supply roller 33 is disposed so as to enter the developing roller 6 in the radial direction.

  Both end portions of the shafts of the developing roller 6 and the developer supply roller 33 are rotatably supported by driving side bearings 38 and non-driving side bearings 39 attached to both side surfaces of the developing frame 29, respectively.

  Further, a developing roller gear 40 and a supply roller gear 41 are disposed at the driving side end portions of the developing roller core material 6a of the developing roller 6 and the developer supply roller core material 33a of the developer supply roller 33, respectively. Are engaged. The development drive input gear 42 includes a development drive coupling 42a, and a drive output coupling (not shown) on the apparatus body 2 side is engaged to transmit a drive force of a drive motor (not shown) of the apparatus body 2. Then, the developing roller 6 and the developer supply roller 33 are rotationally driven at a predetermined speed.

  Here, FIG. 1A is an exploded perspective view showing an example of the configuration of the developing blade unit according to the present invention, and FIG. 1B is a completed perspective view showing an example of the configuration of the developing blade unit according to the present invention. As shown in FIG. 1, the developing blade unit 30 includes a developing blade 31 and a support metal plate 32. Here, the arrow X direction in the figure is referred to as the longitudinal direction, and the Y direction is referred to as the short direction.

  As shown in FIG. 1A, the developing blade 31 is a thin stainless steel plate having a thickness of about 100 μm, and the free end of the developing blade 31 in the short direction is the rotation direction of the developing roller 6 (FIG. 3B). This is a portion that abuts in the counter direction with respect to (arrow E direction). The support sheet metal 32 is a long sheet metal having a length equivalent to that of the developing blade in the longitudinal direction and having a thickness of about 1 mm. The contact region 32b where the developing blade and the support sheet metal partially overlap in the short direction is welded, bonded, or the like. Unitized by fixing with. In the developing blade unit 30, the support sheet metal 32 is fixed to the developing frame 29 with screws 74 or the like. The detailed configuration of the developing blade unit 30 will be described later.

  As shown in FIG. 3B, the developing blade lower seal member 36 is disposed so as to fill a gap in the entire longitudinal direction between the developing frame 29 and the developing blade unit 30 to prevent toner leakage. . The detailed configuration of the developing blade lower seal member 36 will be described later.

  As shown in FIG. 6, the development end seal members 34 </ b> L and 34 </ b> R are disposed on the development end seal attachment seating surfaces 34 zL and 34 zR at both ends of the opening 29 b of the development frame 29. FIG. 7 is a cross-sectional view taken in a direction perpendicular to the axial direction of the developing roller 6 at a position in the longitudinal direction of the developing device, and shows a cross section in the vicinity of the developing end seal attaching seat surface 34zL on the non-driving side. . Since the driving side has the same configuration, the description of the same part is omitted.

  As shown in FIG. 7, the developing end seal attaching seat surface 34 z L (34 z R) is a surface that has a gap s of 2 mm from the outer peripheral surface of the developing roller 6 and is concentric with the developing roller 6 and curved in a semicircular shape. . The developing end seal member 34L (34R) has a thickness t (FIG. 9) larger than 2 mm, so that when the developing end seal member 34L (34R) is attached to the developing end seal attaching seat surface 34zL (34zR), the developing roller 6 and the developing frame 29 are filled to prevent toner leakage from the developing roller 6 and the developing frame 29.

  In this embodiment, the distance from the developing end seal attaching seat surface 34zL (34zR) to the outer peripheral surface of the developing roller 6 is 2 mm. However, the developing end seal member is formed by the gap s between the developing frame 29 and the developing roller 6. If the thickness t of 34L (34R) is larger, the distance is not limited. The detailed configuration of the developing end seal member 34L (34R) will be described later.

  As shown in FIG. 6, the flexible sheet member 35 is disposed on the side of the opening 29 b of the developing frame 29 that faces the developing blade 31 so as to contact the developing roller 6. Toner leakage from the gap with the roller 6 is prevented.

  The supply roller shaft seals 37 </ b> L and 37 </ b> R are attached to a portion of the core material 33 a of the developer supply roller 33 that is exposed to the outside of the development frame 29, and the core of the developer supply roller 33 provided on the development frame 29. Toner leakage from the gap between the core material through hole 33h of the material 33a and the core material 33a is prevented.

  As shown in FIG. 3A, the developing device 9 has a pressure spring in the direction in which the developing roller 6 comes into contact with the photosensitive drum 4 (direction of arrow I in FIG. 3B) around the swing center (axis line b). The developing roller 6 is in contact with the photosensitive drum 4 at all times (not shown).

As shown in FIG. 3B, at the time of image formation, the developer supply roller 33 and the developing roller 6 are rotated and rubbed by driving so that the toner in the developing frame 29 is carried on the developing roller 6. . The developing blade unit 30 regulates the thickness of the toner layer formed on the peripheral surface of the developing roller 6 and applies a charge due to frictional charging to the toner with the developing roller 6 by contact pressure.
The charged toner on the developing roller 6 adheres to the electrostatic latent image on the photosensitive drum 4 at the contact portion between the developing roller 6 and the photosensitive drum 4, and the latent image is developed.

《Detailed configuration of developing blade lower seal member》
FIG. 8 is a detailed configuration diagram showing an example of the developing blade lower seal member 36 which is a first developer leakage preventing member according to the present invention. FIG. 9 is a detailed configuration diagram showing an example of the developing end seal member 34 which is the second developer leakage preventing member according to the present invention. 10A is a perspective view showing a process of attaching the developing blade lower seal member 36 to the developing frame 29, and FIG. 10B shows a process of attaching the developing end seal member 34L to the developing frame 29. FIG. FIG. 10C is a perspective view showing a state in which the development end seal member 34L has been attached to the developing frame 29, and in FIGS. 10A, 10B, and 10C, FIG. The lower figure is a partially enlarged view of the upper figure.

  Each drawing shows a state on the non-driving side, and the same attachment is performed on the driving side of the developing frame 29, so that the description of the same portion is omitted.

  As shown in FIG. 8, the developing blade lower seal member 36 has a rectangular parallelepiped shape along the developing blade lower seal member attachment seat surface 36 z (FIG. 10A) of the developing frame 29. As shown in FIG. 8, the developing blade lower seal member 36 includes a base layer 36a and an adhesive layer 36b. The base layer 36a is made of a synthetic resin foam such as polyurethane, synthetic rubber, natural rubber, thermoplastic elastomer, or the like. The base layer 36a may be made of other materials as long as the base layer 36a has good heat resistance and durability and can sufficiently maintain the adhesive strength with the bonding layer 36b.

  The affixing layer 36b is formed of a double-sided tape or a pressure sensitive adhesive. However, the pasting layer 36b may be made of other materials as long as it has flexibility and the adhesive strength to the base layer 36a is sufficiently maintained. Further, the shape of the developing blade lower seal member 36 may be other than a rectangular parallelepiped shape according to the shape of the developing blade lower seal attaching seating surface 36z and the surrounding configuration.

<< Detailed Configuration of Development End Seal Member >>
As shown in FIG. 9, the developing end seal member 34 as the second developer leakage preventing member has a rectangular parallelepiped shape along the developing end seal attaching seat surface 34 z L (FIG. 7) of the developing frame 29. As shown in FIG. 9, the development end seal member 34 includes a surface layer 50, an adhesive layer 51, an intermediate layer 52, and an adhesive layer 53.

  The surface layer 50 is composed of a base fabric 50a and a pile yarn 50b raised from the base fabric 50a or only the base fabric 50a. The surface layer 50 is bonded to the surface of the intermediate layer 52 via an adhesive layer 51 such as a double-sided tape or an adhesive. The base fabric 50a includes a woven fabric made by weaving warp and weft, a knitted fabric made by knitting yarn, and a non-woven fabric that joins fibers together. Nonwoven fabrics include a system in which fibers are bonded by blowing heated steam, a system in which fibers are bonded by melting with heat, and a system in which fibers are entangled using a high-pressure water stream. The raised pile yarn 50b may be in a loop shape, or may be in a state in which the loop is cut and raised one by one.

  Further, in the case of the configuration of only the base fabric 50a, the yarn may be a raised base fabric 50a by performing electrostatic flocking on the base fabric 50a. Materials for the base fabric 50a and the pile yarn 50b include synthetic fibers such as polyethylene, polypropylene, polyester, nylon, acrylic resin, polyethylene terephthalate, semi-synthetic fiber cotton such as rayon, natural fibers such as cotton, or combinations and twisted yarns thereof. The thing which processed is mentioned.

  The intermediate layer 52 is a cushion layer formed of an elastic body. As the material of the intermediate layer 52, a foam of a synthetic resin such as polyurethane, and other materials such as synthetic rubber, natural rubber, and thermoplastic elastomer are used. The intermediate layer 52 may be made of other materials as long as the heat resistance and durability are good and the adhesive strength between the adhesive layer 51 and the adhesive layer 53 is sufficiently maintained.

  The affixing layer 53 is formed of a double-sided tape or a pressure sensitive adhesive. The affixing layer 53 may be made of other materials as long as it has flexibility and sufficient adhesion strength to the intermediate layer 52 is maintained.

  In addition, the development end seal member 34 having a four-layer structure of the surface layer 50, the adhesive layer 51, the intermediate layer 52, and the bonding layer 53 is taken as an example this time, but in the case of the two-layer structure of the surface layer 50 and the bonding layer 53. However, there is no problem in implementing the present invention. In that case, the structure of the surface layer 50 needs to have a certain thickness by using a nonwoven fabric as the material of the base fabric 50a.

  Further, the shape of the developing end seal member 34 may be other than a rectangular parallelepiped shape according to the shape of the developing end seal attaching seating surface 34zL (FIG. 7) and the surrounding configuration. The development end seal member 34 may have various shapes such as an L shape, a T shape, a chamfer at a corner, and a cutout at a part thereof.

<< Attaching process of developing blade lower seal member and developing end seal member >>
Next, the process of attaching the developing blade lower seal member 36 and the developing end seal member 34 to the developing frame 29 will be described with reference to FIG. First, as illustrated in FIG. 10A, the developing blade lower seal member 36 is attached to the developing blade lower seal seat surface 36 z provided in the developing frame 29. The developing blade lower seal seat surface 36z is provided with a marking line 36k. By aligning the end portion 36t in the longitudinal direction of the developing blade lower seal member 36 with the marking line 36k, the developing blade lower seal member 36 is developed. 29 can be pasted at a predetermined position.

  Next, as shown in FIG. 10B, the developing end seal member 34L is attached to the developing end seal attaching seat surface 34zL (see also FIG. 7) provided in the developing frame 29 while being bent. wear. FIG. 7 shows a state where the development end seal member 34L is bent and pasted. FIG. 7 shows a state in which the flexible sheet member 35, the developing blade unit 30, and the developing roller 6 are attached to the developing frame 29, and the end of the developing end seal member 34L on the flexible sheet member 35 side is shown. A lower end 34tL and an end on the developing blade unit 30 side are an upper end 34uL.

  The development end seal member 34L starts to attach the lower end 34tL of the development end seal 34L in accordance with a reference (not shown) of the development end seal attachment seat surface 34zL. Thereafter, the center of the bent developing end seal member 34L is attached along the arc surface formed on the developing end seal attaching seat surface 34zL. Finally, as shown in FIG. 10B, the upper end 34uL of the developing end seal 34L is attached to the developing end seal adhering seat surface 34zL. At this time, the developing blade lower seal member 36 that has already been attached is attached. Paste it over the top. As a result, a connecting portion 80L (see FIG. 10C) that fills the gap between the developing blade lower seal member 36 and the developing end seal member 34 is formed, and toner leakage can be reliably prevented.

<Detailed configuration of development blade unit>
Next, with reference to FIGS. 1, 11, 12, and 13, the detailed structure of the most characteristic developing blade unit according to the present embodiment will be described. FIG. 11 is an exploded front view showing a process of assembling the developing blade unit 30 to the developing frame 29 to which the developing blade lower seal member 36 and the developing end seal members 34L and 34R are attached. Here, as in FIG. 1, the arrow X direction in the drawing is referred to as the longitudinal direction, and the Y direction is referred to as the short direction.

  12 is an explanatory diagram showing the positional relationship among the developing blade lower seal member 36, the developing end seal member 34L, and the developing blade unit 30 when the developing blade unit 30 is assembled to the developing frame 29. 12A is a perspective view of the non-driving side, FIG. 12B is a front view M when viewed from the arrow M in FIG. 12A, and FIG. Is.

  FIG. 13 shows another embodiment of the present invention. When the developing blade unit 30 is assembled to the developing frame 29, the developing blade lower seal member 36, the developing end seal member 34L, and the developing blade unit 30 are shown. 13 (a) is a perspective view of the non-driving side, FIG. 13 (b) is a front view N viewed from the arrow N of FIG. 12 (a), and FIG. (C) shows the H cross section in the front view N. FIG.

  As described above, the developing blade unit 30 is configured by connecting the developing blade 31 made of a stainless steel thin plate or a phosphor bronze thin plate to a support metal plate 32 made of a steel plate. The developing blade 31 and the support metal plate 32 are fixed in a contact region 32b shown in FIG. Fixing is performed by welding, adhesion, or the like.

  As shown in FIG. 11, the support sheet metal 32 is fixed to the developing blade mounting seat surfaces 29zL and 29zR provided at both ends in the longitudinal direction of the developing frame 29 forming the developing device 9 with screws 74 or the like. .

  The developing blade 31 shown in FIG. 1 may use a phosphor bronze thin plate instead of a stainless steel thin plate, and a coating surface of the developing roller 6 coated with polyamide elastomer (PAE). Further, the shape of the tip of the plate constituting the developing blade 31 may be L-shaped, or nylon or a rubber material or the like may be bonded or coated on the contact surface of the developing roller 6 of the developing blade 31. good.

  Further, the developing blade 31 may use rubber or the like instead of the stainless steel thin plate. In that case, a configuration in which rubber or the like is integrally formed on the support metal plate 32 can be mentioned. As the material of the rubber, for example, urethane rubber, silicon rubber, butyl rubber or the like is used. The support sheet metal 32 is made of stainless steel so that development problems due to rust and the like do not occur. Further, the steel plate may be plated with nickel, zinc or the like.

  As shown in FIG. 1, the support metal plate 32 forms discontinuous ridge lines in the ridge line 32 e extending in the longitudinal direction on the developing roller 6 side. Near the center in the longitudinal direction, there is a circular arc portion 73 that is symmetrical to the center of the image forming area in the longitudinal direction and protrudes toward the developing roller 6 toward the center.

  Further, as shown in FIG. 11, the ridgeline 32e is formed in the longitudinal direction in the region including at least the connecting portions 80L and 80R of the developing blade lower seal member 36 and the developing end seal members 34L and 34R described above. It has protrusions 71L and 71R projecting to the 6 side. The projecting portions 71L and 71R protrude toward the developing roller 6 by the same amount in the short direction as the arc end portions 73L and 73R at both ends in the longitudinal direction of the arc portion 73.

  In the longitudinal direction, notches 72L and 72R that are notched in the opposite direction to the developing roller 6 side are formed in the middle of the arc portion 73 and the projecting portion 71L and in the middle of the arc portion 73 and the projecting portion 71R, respectively. ing.

  And here, in the longitudinal direction, the region where the protrusions 71L, 71R are formed is the first region r1, the region where the notches 72L, 72R are formed is the second region r2, and the arc of the support sheet metal 32 A region where the portion 73 is formed is referred to as a third region r3. Further, the distance (free length) from the tip 31e of the developing blade 31 to the contact area 32b in the short direction (Y direction in the figure) is the first area r1, the second area r2, and the third area r3. The first distance L1, the second distance L2, and the third distance L3, respectively.

  With this configuration, as shown in FIG. 1A, assuming that the free length from the developing blade tip 31e, which is the tip of the developing blade 31 in the region r2, to the notches 72L and 72R is L2, in the region r3, In particular, the free length L3 in the region r33 that is the center of the image forming region in the longitudinal direction can be set shorter by ΔL than the free length L2 in the region r2. Here, when the contact pressure of the developing blade 31 to the developing roller 6 is F, the contact pressure F is expressed by the following equation.

E: Longitudinal elastic modulus, I: Secondary moment of section L: Distance from fulcrum to load point (L2, L3, etc. in this embodiment)
x: deflection of the load point, t: plate thickness of the developing blade 31, b: plate width of the developing blade 31, from the above formula, the shorter the distance L from the fulcrum to the load point (L2, L3, etc. in this embodiment) The contact pressure F increases.

  As described above, since the support sheet metal 32 is fixed to the developing blade mounting seat surfaces 29zL and 29zR provided at both ends in the longitudinal direction of the developing frame 29, the supporting member 32 is located near the region r3. 6 is deformed in the opposite direction.

  Due to the deformation of the support member 32, the contact pressure F of the developing blade 31 decreases, whereas, as shown in FIG. 1A, by reducing the free length of the region r3 by ΔL from the region r2, The contact pressure can be increased. As a result, the contact pressure F with respect to the developing roller 6 of the developing blade 31 in the regions r3 and r2 can be made substantially uniform.

  As described above, as shown in FIG. 12B, the support member 32 has a connecting portion between the developing blade lower seal member 36 and the developing end seal member 34L (34R) in the longitudinal direction (X direction in the drawing). In a region r1 including at least 80L (80R), a projecting portion 71L (71R) protruding toward the developing roller 6 is formed. Further, the coupling portion 80L (80R) is partially covered by the protruding portion 71L (71R) formed on the support member 32 also in the short side direction (Y direction in the drawing).

  FIG. 12C shows a G cross section cut in a direction orthogonal to the axis of the developing roller 6 in the region r1 in FIG. As shown in FIG. 12C, in the region r1, the developing blade lower seal member 36 and the developing end seal member 34L (34R) are perpendicular to the surface of the developing blade 31 (in the direction of arrow V in the figure). The connecting portion 80L (80R) is suppressed by the surface 71bL (71bR) forming the protruding portion 71L (71R) of the support metal plate 32 having high rigidity.

As a result, by suppressing the repulsive force T1 of the connecting portion 80L (80R) acting on the developing blade 31, it is possible to prevent the contact pressure F of the developing blade 31 against the developing roller 6 from increasing.
Each drawing of FIG. 12 shows the configuration on the non-driving side of the developing frame 29, but the configuration on the driving side is the same, and the developing roller of the developing blade 32 is configured by taking the same configuration. 6 can be prevented from increasing.

  FIG. 13 shows another embodiment of the present invention. As described above, as shown in FIG. 13B, the support member 32 has a connecting portion 80L between the developing blade lower seal member 36 and the developing end seal members 34L and 34R in the longitudinal direction (X direction in the drawing). , 80R, a protruding portion 71L (71R) protruding toward the developing roller 6 is formed in the region r1 including at least 80R.

Further, as a difference from the previous embodiment, the coupling portion 80L (80R) is not covered with the protruding portion 71L (71R) formed on the support member 32 in the short side direction (Y direction in the drawing).
FIG. 13C shows an H cross section cut in a direction perpendicular to the axis of the developing roller 6 in the region r1 in FIG.

As shown in FIG. 13C, in the region r1, the developing blade lower seal member 36 is protruded from the support plate 32 having high rigidity in the direction perpendicular to the surface of the developing blade 31 (the direction of arrow V in the figure). It is suppressed by the surface 71bL (71bR) forming the portion 71L (71R).
As a result, the repulsive force T2 of the developing blade lower seal member 36 among the repulsive force T1 of the coupling portion 80L (80R) acting on the developing blade 31 and the repulsive force T2 of the developing blade lower seal member 36 is expressed as regions r2, r3. By suppressing the comparison, an increase in the contact pressure of the developing blade 32 to the developing roller 6 can be prevented.

  Each drawing of FIG. 13 shows the configuration on the non-driving side of the developing frame 29, but the configuration on the driving side is the same, and the developing roller of the developing blade 31 is configured by taking the same configuration. 6 can be prevented from increasing. Further, in the present embodiment, the developing blade lower seal member 36 and the developing end seal member 34L (34R) may be configured by a plurality of members.

  Further, as shown in FIG. 11, the protruding positions in the short direction (Y direction in the figure) of the projecting parts 71L and 71R are cut when the center part 73c is the center in the longitudinal direction (X direction in the figure) of the arc part 73. Any position between the notches 72L and 72R and the central portion 73c may be used. That is, the protrusions 71L and 71R cannot exhibit the effects of the present invention unless they protrude from the notches 72L and 72R toward the developing roller 6 in the short direction (Y direction in the figure).

  If the protrusions 71L and 71R protrude too far toward the developing roller 6 in the short direction (Y direction in the figure), the distance (free length L) from the protrusions 71L and 71R to the developing blade tip 31e becomes too small. As a result, the contact pressure F of the developing blade 31 against the developing roller 6 increases. Therefore, the effect of reducing the contact pressure F by suppressing the developing blade lower seal member 36 or the developing end seal member 34L (34R) on the surfaces of the projecting portions 71L and 71R is eliminated.

  For this reason, the protruding positions in the short direction of the protrusions 71L and 71R are positioned in the direction opposite to the developing roller 6 side from the central portion 73c, so that the distance from the protrusions 71L and 71R to the developing blade tip 31e (free length) L) can be secured sufficiently. Therefore, the effect of suppressing the developing blade lower seal member 36 or the developing end seal member 34L (34R) can be sufficiently exerted on the surfaces of the projecting portions 71L and 71R.

  Further, the projecting portions 71L and 71R may be provided directly outside the arc end portions 73L and 73R of the arc portion 73 without forming the notches 72L and 72R in the longitudinal direction (arrow X direction). In this case, the distance (free length L) from the protrusions 71L and 71R to the developing blade tip 31e is set shorter than the distance (free length L) from the arcuate ends 73L and 73R to the developing blade tip 31e. It ’s fine.

  As described above, according to the present invention, in the longitudinal direction of the developing blade 31, the support sheet metal 32 is provided at the position including the coupling portions 80L and 80R where the developing blade lower seal member 36 and the developing end seal members 34L and 34R overlap. Protruding portions 71L and 71R are formed, and the coupling portions 80L and 80R or the developing blade lower seal member 36 are held down. Thereby, the repulsive force of the developing blade lower seal member 36 or the developing end seal members 34L and 34R at the position where the pressure is particularly likely to increase can be suppressed by the support metal plate 32 having high rigidity. As a result, it is possible to make the contact pressure in the longitudinal direction of the developing blade 31 uniform, prevent an increase in the end pressure, and provide the developing device 9 with less image density in the longitudinal direction.

  FIG. 14 shows another embodiment of the present invention. When the developing blade unit 30 is assembled to the developing frame 29, the developing blade lower seal member 36, the developing end seal member 34L, and the developing blade unit 30 are shown. FIG. 14A is a perspective view of the non-driving side, and FIG. 14B is a front view P when viewed from the arrow P of FIG. 14A. It is.

  The difference from the first embodiment is that the connecting portion 80L (80R) between the developing blade lower seal member 36 and the developing end seal member 34L (34R) is not provided.

As shown in FIG. 14, the developing end seal 34L is attached to the developing end seal attaching seat surface 34zL. At this time, the developing end seal 34L is attached in close contact with the developing blade lower seal member 36 already attached. As a result, a close contact surface 81L that fills the gap between the developing blade lower seal member 36 and the developing end seal member 34L is formed, and toner leakage can be reliably prevented.
The support member 32 has a protruding portion 71L that protrudes toward the developing roller 6 in an end portion in the longitudinal direction (X direction in the drawing) at least in a region r1 that includes at least a part of the attaching region of the developing end seal member 34L (34R). (71R) is formed.

  In the region r1, the developing blade lower seal member 36 is held down by the protruding portion 71L of the support metal plate 32 having high rigidity in a direction perpendicular to the surface of the developing blade 31. As a result, the repulsive force of the developing blade lower seal member 36 acting on the developing blade 31 can be suppressed as compared with the regions r3 and r2, and an increase in the contact pressure of the developing blade 32 to the developing roller 6 can be prevented.

  Each drawing of FIG. 14 shows the configuration on the non-driving side of the developing frame 29, but the configuration on the driving side is the same, and the developing roller of the developing blade 32 is configured by taking the same configuration. 6 can be prevented from increasing.

  FIG. 15 shows another embodiment of the present invention. When the developing blade unit 30 is assembled to the developing frame 29, the developing blade lower seal member 36, the developing end seal member 34L, and the developing blade unit 30 are shown. 15 (a) is a perspective view of the non-driving side, and FIG. 15 (b) is a front view Q when viewed from the arrow Q of FIG. 15 (a). Is. The difference from the first embodiment is that the connecting portion 80L (80R) between the developing blade lower seal member 36 and the developing end seal member 34L (34R) is not provided.

  As shown in FIG. 15, the developing end seal 34L is attached to the developing end seal attaching seat surface 34zL, and in this case, the developing end seal 34L is attached in close contact with the already attached developing blade lower seal member 36. Thereby, the contact surface 82L that fills the gap between the developing blade lower seal member 36 and the developing end seal member 34 is formed, and toner leakage can be reliably prevented.

  The support member 32 has a protruding portion 71L that protrudes toward the developing roller 6 in an end portion in the longitudinal direction (X direction in the drawing) at least in a region r1 that includes at least a part of the attaching region of the developing end seal member 34L (34R). (71R) is formed.

  In the region r1, the developing blade lower seal member 36 and the developing end seal member 34L are held down by the protruding portion 71L of the highly rigid support sheet metal 32 in a direction perpendicular to the surface of the developing blade 31. As a result, the repulsive force of the developing blade lower seal member 36 acting on the developing blade 31 is suppressed as compared with the regions r2 and r3, and further the repulsive force of the developing end seal member 34L is suppressed, so that the developing roller of the developing blade 32 6 can be prevented from increasing.

  Here, the protruding portion 71L suppresses both the repulsive force of the developing blade lower seal member 36 acting on the developing blade 31 and the repelling force of the developing end seal member 34L, but in the longitudinal direction of the protruding portion 71L (see FIG. Only the repulsive force of the developing end seal member 34L may be suppressed by changing the formation position in the middle X direction). As a result, the repulsive force of the developing end seal member 34L acting on the developing blade 31 can be suppressed, and an increase in the contact pressure of the developing blade 32 to the developing roller 6 can be prevented.

  Each drawing of FIG. 15 shows the configuration on the non-driving side of the developing frame 29, but the configuration on the driving side is also the same, and the developing roller of the developing blade 32 is configured by taking the same configuration. 6 can be prevented from increasing. Further, in the present embodiment, the developing blade lower seal member 36 and the developing end seal member 34L (34R) may be configured by a plurality of members.

  As described above, the support sheet metal 32 forms the protrusions 71L and 71R in the region r1 including a part of the attachment region of the development end seal members 34L and 34R in the longitudinal direction of the developing blade 31, and develops. The blade lower seal member 36 and the development end seal members 34L and 34R are held down. Thereby, the repulsive force of the developing blade lower seal member 36 or the developing end seal members 34L and 34R at the position where the pressure is particularly likely to increase can be suppressed by the support metal plate 32 having high rigidity. As a result, it is possible to make the contact pressure in the longitudinal direction of the developing blade 31 uniform, prevent an increase in the end pressure, and provide the developing device 9 with less image density in the longitudinal direction.

1 electrophotographic image forming apparatus (image forming apparatus), 2 apparatus main body, 3 apparatus opening / closing door,
4 electrophotographic photosensitive member (photosensitive drum), 4a drum drive coupling,
5 charging roller, 6 developing roller (developer carrier), 6a developing roller core,
7 Cleaning blade, 8 Cleaning unit, 9 Developing device,
10 exposure window, 11 intermediate transfer belt unit, 12 transfer belt,
13 drive roller, 14 turn roller, 15 tension roller,
16 Primary transfer roller, 17 Secondary transfer roller, 18 Feeding unit,
19 paper feed tray, 20 paper feed roller, 21 fixing unit, 22 discharge unit,
23 discharge tray, 24 driving side cover member, 25 non-driving side cover member,
26 cleaning container, 26a waste toner container, 27 charging roller bearing,
28 charging roller pressure spring, 29 developing frame, 29b opening, 29c toner accommodating portion,
29zL, 29zR Development blade mounting seat surface,
30 developing blade unit (developer regulating member), 31 developing blade,
31e tip of developing blade, 32 support sheet metal, 32b contact area, 32e ridge line,
33 developer supply roller, 33a developer supply roller core,
34, 34L, 34R Development end seal member (second developer leakage prevention member),
34 tL lower end, 34 uL upper end,
34zL, 34zR development end seal pasting seat surface, 35 flexible sheet member,
36 developing blade lower seal member (first developer leakage preventing member), 36a base layer,
36b bonding layer, 36k marking line, 36t end,
36z Development blade lower seal pasting seat surface, 37L, 37R Supply roller shaft seal,
38 driving side bearing, 39 non-driving side bearing, 40 developing roller gear,
41 Supply roller gear, 42 Development drive input gear, 42a Development drive coupling,
43 cartridge tray, 50 surface layer, 50a base fabric, 50b pile yarn,
51 adhesive layer, 52 intermediate layer, 53 adhesive layer, 71L, 71R protrusion,
71bL face, 72 notch, 73 arc, 73c center,
73L, 73R arc ends, 74 screws, 80L, 80R joints,
81L adhesion surface, 82L adhesion surface, S recording medium, L free length,
LB laser scanner, Z laser light

Claims (4)

A developing frame housing the developer;
A developer carrying member carrying the developer;
In a developing device having a developer regulating member that regulates the developer on the developer carrier by bringing one end portion in a direction perpendicular to the axis of the developer carrier into contact with the developer carrier.
The development regulating member is
A developing blade in contact with the developer carrier;
A support sheet metal that supports the developing blade,
The support sheet metal has a contact area in contact with the developing blade;
The developing blade is coupled to the support sheet metal at the contact area;
The support sheet metal is fixed to the developing frame at both ends in the axial direction of the developer carrier,
A first developer leakage preventing member that seals between the development regulating member and the developing frame in the axial direction of the developer carrying member;
Second developer leakage prevention member that seals between the developer carrier and the development frame and between the development regulating member and the development frame at both ends in the axial direction of the developer carrier. And
Having both ends of the axial direction of the developer carrier of the first developer leakage preventing member and the coupling portion where the second developer leakage preventing member overlaps;
In the end region including the coupling portion in the axial direction of the developer carrier, the distance from the one end portion of the development regulating member to the contact region in the direction orthogonal to the axis of the developer carrier is A protrusion that is one distance away,
The distance between the one end of the development regulating member and the contact area in the direction orthogonal to the axis of the developer carrier is a second distance on the inner side in the axial direction of the developer carrier of the protrusion. And has a second region
On the inner side of the second region in the axial direction of the developer carrier, a distance from the one end portion of the development regulating member to the contact region in a direction orthogonal to the axis of the developer carrier is a third distance. Has a third region that is a distance of
The relationship between the first distance, the second distance, and the third distance is second distance> first distance ≧ third distance,
The developing device, wherein the protruding portion suppresses at least a part of the first developer leakage preventing member. A developing frame housing the developer;
A developer carrying member carrying the developer;
In a developing device having a developer regulating member that regulates the developer on the developer carrier by bringing one end portion in a direction perpendicular to the axis of the developer carrier into contact with the developer carrier.
The development regulating member is
A developing blade in contact with the developer carrier;
A support sheet metal that supports the developing blade,
The support sheet metal has a contact area in contact with the developing blade;
The developing blade is coupled to the support sheet metal at the contact area;
The support sheet metal is fixed to the developing frame at both ends in the axial direction of the developer carrier,
A first developer leakage preventing member that seals between the development regulating member and the developing frame in the axial direction of the developer carrying member;
Second developer leakage prevention member that seals between the developer carrier and the development frame and between the development regulating member and the development frame at both ends in the axial direction of the developer carrier. And
In the end region in the axial direction of the developer carrier, the distance from the one end portion of the development regulating member to the contact region in the direction orthogonal to the axis of the developer carrier is the first distance. Has a protrusion,
The distance between the one end of the development regulating member and the contact area in the direction orthogonal to the axis of the developer carrier is a second distance on the inner side in the axial direction of the developer carrier of the protrusion. And has a second region
On the inner side of the second region in the axial direction of the developer carrier, a distance from the one end portion of the development regulating member to the contact region in a direction orthogonal to the axis of the developer carrier is a third distance. Has a third region that is a distance of
The relationship between the first distance, the second distance, and the third distance is second distance> first distance ≧ third distance,
The developing device according to claim 1, wherein the protruding portion suppresses at least a part of either the first developer leakage preventing member or the second developer leakage preventing member. In the process cartridge that can be attached to and detached from the main body of the electrophotographic image forming apparatus,
An electrophotographic photosensitive drum;
A cleaning device having a cleaning frame for supporting the electrophotographic photosensitive drum;
A developing frame housing the developer;
A developer carrying member carrying the developer;
A developing device having a developer regulating member that regulates the developer on the developer carrier by bringing one end portion in a direction orthogonal to the axis of the developer carrier into contact with the developer carrier;
Have
The development regulating member is
A developing blade in contact with the developer carrier;
A support sheet metal that supports the developing blade,
The support sheet metal has a contact area in contact with the developing blade;
The developing blade is coupled to the support sheet metal at the contact area;
The support sheet metal is fixed to the developing frame at both ends in the axial direction of the developer carrier,
A first developer leakage preventing member that seals between the development regulating member and the developing frame in the axial direction of the developer carrying member;
Second developer leakage prevention member that seals between the developer carrier and the development frame and between the development regulating member and the development frame at both ends in the axial direction of the developer carrier. And
Having both ends of the axial direction of the developer carrier of the first developer leakage preventing member and the coupling portion where the second developer leakage preventing member overlaps;
In the end region including the coupling portion in the axial direction of the developer carrier, the distance from the one end portion of the development regulating member to the contact region in the direction orthogonal to the axis of the developer carrier is A protrusion that is one distance away,
The distance between the one end of the development regulating member and the contact area in the direction orthogonal to the axis of the developer carrier is a second distance on the inner side in the axial direction of the developer carrier of the protrusion. And has a second region
On the inner side of the second region in the axial direction of the developer carrier, a distance from the one end portion of the development regulating member to the contact region in a direction orthogonal to the axis of the developer carrier is a third distance. Has a third region that is a distance of
The relationship between the first distance, the second distance, and the third distance is second distance> first distance ≧ third distance,
The process cartridge according to claim 1, wherein the protruding portion suppresses at least a part of the first developer leakage preventing member. In the process cartridge that can be attached to and detached from the main body of the electrophotographic image forming apparatus,
An electrophotographic photosensitive drum;
A cleaning device having a cleaning frame for supporting the electrophotographic photosensitive drum;
A developing frame housing the developer;
A developer carrying member carrying the developer;
A developing device having a developer regulating member that regulates the developer on the developer carrier by bringing one end portion in a direction orthogonal to the axis of the developer carrier into contact with the developer carrier;
Have
The development regulating member is
A developing blade in contact with the developer carrier;
A support sheet metal that supports the developing blade,
The support sheet metal has a contact area in contact with the developing blade;
The developing blade is coupled to the support sheet metal at the contact area;
The support sheet metal is fixed to the developing frame at both ends in the axial direction of the developer carrier,
A first developer leakage preventing member that seals between the development regulating member and the developing frame in the axial direction of the developer carrying member;
Second developer leakage prevention member that seals between the developer carrier and the development frame and between the development regulating member and the development frame at both ends in the axial direction of the developer carrier. And
In the end region in the axial direction of the developer carrier, the distance from the one end portion of the development regulating member to the contact region in the direction orthogonal to the axis of the developer carrier is the first distance. Has a protrusion,
The distance between the one end of the development regulating member and the contact area in the direction orthogonal to the axis of the developer carrier is a second distance on the inner side in the axial direction of the developer carrier of the protrusion. And has a second region
On the inner side of the second region in the axial direction of the developer carrier, a distance from the one end portion of the development regulating member to the contact region in a direction orthogonal to the axis of the developer carrier is a third distance. Has a third region that is a distance of
The relationship between the first distance, the second distance, and the third distance is second distance> first distance ≧ third distance,
2. A process cartridge according to claim 1, wherein the protruding portion suppresses at least a part of either the first developer leakage preventing member or the second developer leakage preventing member.